On the differences between Danais Limniace, Cram. and Danais melissa Cram

In „The Rhopalocera of Java”, Danaidae, Satyridae, Ragadidae and Elymniadae by M. C. Piepers and P. C. T. Snellen (the Hague, H. Nyhoff, 1913) I have found on page 80, that D. melissa Cram. should be synonymous with D. limniace Cram. On the same page one read: „The forms of this species (limniace Cram.) have been dealt with extensively by Fruhstorfer in „Berliner Entom. Zeitschr.”, 1899, and by Dr. L. Martin in „Deutsche Entom. Zeitschr. Iris”, 1910, where they have based several species and subspecies on these various forms; the latter attributes them to climatic influences. I suspect that here again we have simply to deal with phenomena of colour evolution; the specially pronounced spreading of the white, which plays the chief role here, being doubtless nothing else.” Always it will be a danger to determine a butterfly only by its external morphological characters, especially by its pattern and colour, even when people will explain the differences of pattern and colour by phenomena of colour evolution. Mr. Piepers is here not right, because there are also anatomical differences, which separate the two forms of Danais specifically. In „Die Grossschmetterlinge der Erde”, Tom. 9, pag. 202, Mr. Fruhstorfer has published, that the vulvae of the two quoted species as well as the uncus are different. He wrote the following: „Untersuchungen der Generationsorgane (melissa and septentrionis) haben aber die specifische Gleichartigkeit der habituell so differenzierten Formen ergeben. Nur der Uncus zeigt eine leichte Abweichung, indem er bei septentrionis distal scharf abgeschnitten, bei melissa distal leicht ausgewölbt erscheint. Die Valve ist gleichfalls nach aussen vertikal scharf abgesetzt und führt einen fingerförmigen Dorn mit stumpfer Spitze, der je nach der Lokalität in der Länge wechselt”, and on page 204: „Die Valve (of limniace) ist sehr verschieden von jener der melissa-Formenreihe, joch- oder damensattelförmig, distal nicht spitz bedornt, sondern mit kräftigem Eckzacken bewehrt. Uncus robuster, manchmal nach aussen glatt abgeschnitten.